The use of IsDigit () function and Isxdigit () function in C language _c language

C language IsDigit () function: To determine whether a character is an Arabic numeral
header file:

#include <ctype.h>

To define a function:

int isdigit (int c);

Function Description: Check whether the parameter C is Arabic numerals 0 to 9.

Return value: Returns true if parameter C is Arabic, otherwise null (0).

Additional description: This is a macro definition, not a true function.

Example: Find the characters in the STR string that are Arabic numerals.

#include <ctype.h>
Main () {
 char str[] = "123@ #FDsP [E?";
 int i;
 for (i = 0; Str[i]!= 0; i++)
  if (IsDigit (str[i)))
   printf ("%c be an digit character\n", str[i));

Execution results:

1 is a digit character
2 is a digit character
3 is a digit character

C language Isxdigit () function: To determine whether a character is a 16 binary number

Header file:

#include <ctype.h>

To define a function:

int isxdigit (int c);

Function Description: Check whether the parameter C is a 16 binary number, as long as C is one of the following conditions to detect success.

16 binary number: 0123456789ABCDEF.

Return value: If parameter C is a 16-digit number, it returns a non-0, otherwise it returns 0.

Additional description: This is a macro definition, not a true function.

Example: finds characters in string str that are hexadecimal digits.

#include <ctype.h>
Main () {
 char str[] = "123c@ #FDsP [E?";
 int i;
 for (i = 0; Str[i]!= 0; i++)
  if (Isxdigit (str[i)))
   printf ("%c be a hexadecimal digits\n", str[i]);

Execution results:

1 is a hexadecimal digits
2 are a hexadecimal digits
3 is a hexadecimal digits
c is a hexadecimal DIGITS
   f is a hexadecimal digits
D are a hexadecimal digits
e is a hexadecimal digits